From the article:
Tactus has created a thin layer that can replace the Gorilla Glass on top of the touch sensor and display layers of a smartphone or tablet. The surface of that layer is a semi-elastic polymer under which there are little channels filled with a special transparent micro-fluid. To make buttons appear (for a keyboard, a game controller, whatever), you can increase the fluid pressure in a certain area. The added fluid physically stretches and raises the polymer surface.
Presto! Real buttons on your previously flat screen.
Tactus Technology - CES 2013 from Tactus on Vimeo.
